The present invention relates to a radio paging receiver and, more particularly, to an improvement in the control means for the display and alert tones.
Radio paging receivers with display function in the prior art generate alert tones upon reception of a selective calling signal and store display information (or a message) subsequent to the selective calling signal. The alert tone stops when a switch is pressed down, and the stored display information is simultaneously displayed on a visual display device. Examples of such receivers are disclosed in U.S. Pat. No. 4,091,373 issued to J. Nakamura and also in U.S. Pat. No. 4,249,165 issued to T. Mori and assigned to the assignee of the present application. In these radio paging receivers, stored display information can be displayed, when needed, by depressing a switch; however, as the switch is released, the information on the display device immediately disappears. In order to confirm the displayed information, the switch must be continuously depressed.
In order to obviate such inconvenience, there has been proposed a selective paging receiver provided with a timer which is activated when a switch is pressed down to control the display on the display device by the output of the timer. Reference is made to the Japanese Patent Publication No. 55-2099 dated Jan. 18, 1980. According to the system described in this reference, manual operation of a switch can operate the receiver to reset a sound circuit for alert tones and at the same time to activate a display device for a predetermined time preset by the timer function thereof. The receiver, however, still is defective in that the information can not be visually presented while the alert tone is present. Further, if the time for the visual display is preset for a predetermined short period of time, a longer information can not be displayed while if it is preset for a predetermined longer period of time, a short information unavoidably leaves a void space.